1. Field of the Invention
This invention relates to a liquid container, a liquid supply system and a recording apparatus using the liquid container, a circuit module for a liquid container and a substrate, and a liquid storage cartridge and particularly relates to the liquid container, the liquid supply system and the recording apparatus using the liquid container, the circuit module for a liquid container, and the substrate which are structured that information of a condition of the liquid container such as the condition of an amount of the residual ink in an ink tank used for the ink jet recording is displayed by driving a light emitting portion such as an LED.
2. Related Background Art
Recently, diffusion of digital cameras contributes to increase the number of non-PC recording, namely, printing by directly connecting to ink jet printers (hereinafter simply the recording apparatus or printer) functioning as both the digital camera and the recording apparatus without a personal computer (PC). Furthermore, the number of non-PC recording, namely, printing by directly connecting to the ink jet printer, is increasing where the printing job is performed by directly loading a card type information recording medium, removable from the digital camera, in the printer so as to transfer data. Generally, it is known that the amount of the residual ink within the ink tank is to be confirmed on a monitor through a PC. However, it is beneficial and especially advantageous for the non-PC recording to learn about the condition of the ink tank such as the amount of the residual ink within the ink tank and information as to whether the ink tank is properly mounted without using the PC. When the user uses the printer and for example notices that the amount of ink is low (little), the user can replace the ink tank prior to the printing job in order to obviate a problem of practically not being able to record due to the insufficient amount of ink during the recording job. If the user notices about the inappropriate setting of the ink tank, the user can remount the ink tank prior to the printing job, thereby ascertaining the setting of the ink tank.
Conventionally, a display element such as the LED is known as a structure of informing the user of the condition of the ink tank. Japanese Patent Application Laid-Open No. H04-275156 discloses that two LEDs and recording means (hereinafter memory) are provided in the ink tank integrated with a recording head and that each LED flashes in correspondence to the information of two levels of the amount of the residual ink recorded in the memory. Japanese Patent Application Laid-Open No. 2002-301829 discloses that a lamp flashes corresponding to the information of the amount of the residual ink as well. In that reference, it is also disclosed that the above-explained lamp is provided in each of four ink tanks used in the printer.
Recently, there is a demand for printers to be more power saving from ecology standpoint. Due to the fact that mobile notebook computers and digital cameras have been wide-spread, the printers are used under the static environment such as in an office and a house as well as under the dynamic environment functioning as mobile printers, thereby widening the operating environment. Different from the static environment where power supply is not a major concern because the printer may be connected to a general household power supply and commercial power supply, the dynamic environment forces the printer to operate under the limited power supply such as by batteries. Accordingly, in order to structure such mobile printers, more power saving solution is in demand.
Japanese Patent Application Laid-Open Nos. H04-275156 and 2002-301829 simply disclose conditions where display devices on the ink tanks are mounted in the printer bodies. In consideration of the structure that the ink tank is mountable on and removable from the printer body, the power is supplied from the printer to the display device or memory under this condition.
Here, the display device and the memory mounted on the ink tank each need to be controlled to be driven and accessed with an appropriate timing, and therefore proper power supply is highly desirable for the power saving standpoint. However, Japanese Patent Application Laid-Open Nos. H04-275156 and 2002-3018290 do not suggest such a power saving structure.
Generally, recent printers perform color recording using inks of black, yellow, magenta, and cyan, and because of the needs for higher picture quality, colors such as light color magenta and light color cyan have been used in addition to the above four colors. Some printers use inks of spot colors such as red and blue. In these cases, the printers need to carry plural ink tanks corresponding to the number of ink colors.
As such, when the printer carries plural ink tanks with the memories storing various printer information, all memories need to be electrically connected with each other to transfer signals with a main control portion (such as a CPU) of the printer body. Therefore, as the number of ink tanks mounted thereon, namely, the number of memories, increases, signal lines to be connected thereto must also increase.
Also, there is a structure where each circuit, which connects between an electric contact point at the ink tank side for sending and receiving signals and an electric contact point at the printer, is provided on a individually predetermined position in the above plural ink tanks. In this structure, if the color information is detected as communicating with the ink tank, which indicates that the amount of ink is little and the display portion of the ink tank at the corresponding mounting position is controlled to flash, the user accurately recognizes the little amount of the residual ink in the ink tank based on the displayed information.
However, in the structure that the signal line is individually provided at every ink tank or mounting position, the number of signal lines further increases so as to perform the above control. It is not preferable the tendency of the increase in the number of mounted ink tanks, and this structure raises problems of more complicated wiring and higher cost. Especially, considering that the different elements, which require different amount of electric energy for driving, are mounted on the ink tank, each element must be supplied with proper electric energy. In this case, the electric supply lines are arranged to correspond to this structure, which increases the number of wiring and creates the complicated structure.